It is proposed to continue expansion of the diabetic Chinese hamster colony and development of lines with different genotypic and phenotypic expressions of diabetes. Particular emphasis will be placed on the Fl hybrids of pure sublines, to establish if hybridization enhances fertility and vigor. Characterization of genetic diabetes in these animals will be continued in the laboratories of the Internal Investigators of the CHPP. Studies will focus on the kinetics of insulin, glucagon and somatostatin secretion, the relationship of islet cell metabolism to impaired hormone secretion, neurologic and pathologic changes, changes in islet monamines in relation to diabetes and the effect of pancreatic and islet cell transplant on many of these parameters.